Heretofore, the three-chamber gas meters of the prior art have all required flag assemblies externally connected of the chambers, or to the diaphragms or bellows so as to greatly increase the size of the meter and the complexity of the linkage. Also, the housing and chamber configurations have been bulky. Thus, assembly and subsequent adjustment or accuracy became more complex or difficult to obtain. This also added to the cost of making the meter, especially in mass production thereof.